Beginner's question about antennas

[shushi]

TL;DR

Can multiple antennas share a dish without interference?

Hello!

This may be an obvious idea and I feel silly for asking this, but just out of curiosity, if I have a large dish satellite where I could fit three antenna transmitters in the center that send different types of signals (a broad-band radio antenna, an ultrasonic antenna/sensor, and a microwave radio GPS antenna [an additional one that I also thinking about is a wifi one, but overall I'm considering just giving it its own dish]) if those three antennas were connected to bandpass filters, could I successfully create a multi antenna dish that transmits different signals without much interference?

 

[trurle]

Such arrangement is quite common in high-end radars and radio-telescopes. It is called "multibeam antenna". Not very useful for simultaneous tracking of independent targets as seems to be your case though.

 

[anorlunda]

But WiFi you don't want to point to the sky. People have built very successful directional WiFi antennas from old Pringle cans.

 

[davenn]

Summary: Can multiple antennas share a dish without interference?

and a microwave radio GPS antenna

You don't was a GPS antenna (GPS is receive) in a dish, as the satellites are not fixed in orbit,
rather they are many different orbits all over the sky.
GPS antennas are usually "relatively" fixed and have a horizon to horizon 360 deg view

 

[tech99]

How will you place them all in the same position, at the focus? Multiband antennas are possible but not easy. Why not use the broadband antenna and then separate the signals with filters. You seem to be interested in just the 1 to 2 GHz region.
By the way, the ultrasonic detector is not radio so will need a solid dish, and of course, it cannot utilise the broadband antenna.